C#maj11/13#5/A for Piano has the notes C# F F# A A# C . Listen to it and learn about its interval structure: R 3 4 #5 6 7.

Chord Constructionmajor chord: chord has major third (R + 3)chord is (aug): major + has augmented 5th (R´+ #5)chord is maj7#5: augmented chord with a major interval on the 7th (R,3,#5) + 7chord is maj11#5: chord maj7#5 with added 4th (11th)chord is maj11/13#5: chord maj11#5 with added 6th (13th)